The present invention is directed toward a knee strap for treating chondromalacia patella and more particularly toward such a device which is easy to apply and comfortable to wear and which significantly decreases the pain and discomfort suffered by patients with this condition.
It is estimated that approximately one out of every five persons in this country has or will have knee trouble of some kind. The majority of such persons will develop what is commonly called chondromalacia patella. As is known in the art, this term means the softening or degeneration of the undersurface of the patella or kneecap.
Many factors contribute to a person developing chondromalacia patella although the exact mechanism and reason for developing the condition is not truly known. Briefly, if the leg structure is such that the patella is continuously forced outwardly, it will bump against the condyles or bulbous ends of the femur. This causes uneven pressure on the patella. That is, the surface area is less and a given force will be multiplied many times leading to degeneration, inflammation of the synovial lining of the joint, swelling, pain and crepitus on knee motion. Some persons ultimately require surgery to correct this problem.
Another problem with the patello-femoral mechanism is subluxation of the patella. This is the dislocation, usually laterally, of the patella. The patella slips out of the groove formed by the condyles and further traumatizes the undersurface of the patella.
Basically, the solution to the problem of chondromalacia patella and patellar subluxation is to control the patella and force it to stay in proper alignment. Proper alignment keeps the pressures on the underside of the patella reduced by sharing the load over a larger area.
There are knee braces on the market which attempt to solve the foregoing problems. These are basically of two types. Each is a large sleeve-type member which either pulls over the leg or is fastened about the knee with straps or Velcro or the like. The first type of brace has an opening around the patella and includes pads or buttresses laterally, medially or above the patella. The object of this type of brace is to prevent a patella from riding or shifting laterally. The sleeve-type of brace without the opening for the patella attempts to force the patella into the groove of the condyles by compression, thus increasing the surface area under the patella which decreases the pressure area.
These prior art devices suffer from many disadvantages. Among others, it is difficult to keep the braces in place since they have a tendency to creep, ride down or bunch up behind the knee. These devices restrict knee motion due to bunching in back of the knee and they can cause heat rash due to poor evaporation of perspiration. The sleeve-type devices are difficult for older patients to pull on and cannot be loosened if they become uncomfortable in which case the device is usually removed and therefore is of no help. These prior devices also provide poor stabilization of the patella which moves in multiple planes and directions. Even further, the appearance of these prior braces is not particularly pleasing and they are, therefore, not usually worn by persons other than athletes or other sports minded individuals. These relatively expensive prior devices are also normally not available in smaller sizes to fit children who very often have patellar subluxation problems.